Heat exchanger

ABSTRACT

A heat exchanger includes a plurality of heat exchange tubes stacked with a gap through which a first fluid can pass. The heat exchange tube includes: an internal flow path through which a second fluid for exchanging heat with the first fluid and which includes a folded portion; a plurality of slits provided between two flow path portions in the internal flow paths, the two flow path portions each extending from the folded portion and facing each other at an interval; and a plurality of protruding support portions in contact with another adjacent heat exchange tube to form the gap. As viewed in a stacking direction of the plurality of heat exchange tubes, at least one of the plurality of slits extends in a state where a center in an extending direction thereof deviates from a straight line connecting the two adjacent protruding support portions.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to a heat exchanger.

Description of the Related Art

Japanese Patent No. 6089172 discloses a heat exchanger in which a plurality of fin-shaped heat exchange tubes having an internal flow path through which water (fluid) flows are stacked with a gap. In order to form a gap through which air (fluid) to be heat-exchanged passes between the plurality of heat exchange tubes, each of the heat exchange tubes is provided with a plurality of embossed portions in contact with another adjacent heat exchange tube.

SUMMARY OF THE INVENTION

Incidentally, in the case of a heat exchanger configured by stacking a plurality of fin-shaped heat exchange tubes as described in Japanese Patent No. 6089172, it is necessary to accurately form a gap between the heat exchange tubes. Otherwise, the flow path resistance between the heat exchange tubes may cause variation, and as a result, the heat exchange rate of the heat exchanger may cause variation.

Thus, an object of the present disclosure is to accurately form a gap between heat exchange tubes in a heat exchanger configured by stacking a plurality of heat exchange tubes.

In order to solve the above problem, according to one aspect of the present disclosure, provided is a heat exchanger including a plurality of heat exchange tubes stacked with a gap through which a first fluid is passable. Each of the heat exchange tubes includes: an internal flow path through which a second fluid for exchanging heat with the first fluid flows, the internal flow path including a folded portion, an inflow-side connection portion which communicates with the internal flow path and into which the second fluid flows, an outflow-side connection portion which communicates with the internal flow path and from which the second fluid flows out, a plurality of slits provided in a portion of the heat exchange tube between two flow path portions in the internal flow paths, the two flow path portions respectively extending from the folded portions and facing each other at an interval, and a plurality of protruding support portions in contact with another adjacent heat exchange tube to form the gap. As viewed in a stacking direction of the plurality of heat exchange tubes, at least one of the plurality of slits extends in a state where a center in an extending direction of the plurality of slits deviates from a straight line connecting the two adjacent protruding support portions.

According to the present disclosure, in the heat exchanger configured by stacking a plurality of heat exchange tubes, the gap between the heat exchange tubes can be accurately formed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a heat exchanger according to a first preferred embodiment of the present disclosure;

FIG. 2 is a partial cross-sectional view of the heat exchanger taken along line A-A in FIG. 1;

FIG. 3 is a perspective view of a heat exchange tube of the heat exchanger according to the first preferred embodiment;

FIG. 4 is a top view of the heat exchange tube according to the first preferred embodiment;

FIG. 5 is a cross-sectional view of the heat exchange tube taken along line B-B in FIG. 4;

FIG. 6A is a diagram showing a simplified model of a heat exchange tube of a comparative example provided with a slit and two protruding support portions;

FIG. 6B is a diagram showing a simplified model of a heat exchange tube of a comparative example torsionally deformed by stacking;

FIG. 7A is a diagram showing a simplified model of a heat exchange tube of an example;

FIG. 7B is a diagram showing a simplified model of a heat exchange tube of a preferred example;

FIG. 8 is a cross-sectional view of a heat exchange tube of a heat exchanger according to a second preferred embodiment of the present disclosure;

FIG. 9 is a perspective view of a heat exchange tube of a heat exchanger according to a third preferred embodiment of the present disclosure;

FIG. 10 is a cross-sectional view of a heat exchange tube according to the third preferred embodiment;

FIG. 11 is a diagram showing an example of an internal flow path of a heat exchange tube;

FIG. 12 is a diagram showing another example of an internal flow path of a heat exchange tube; and

FIG. 13 is a diagram showing a different example of an internal flow path of a heat exchange tube.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A heat exchanger according to one aspect of the present disclosure includes a plurality of heat exchange tubes stacked with a gap through which a first fluid is configured to pass. Each of the heat exchange tubes includes: an internal flow path through which a second fluid for exchanging heat with the first fluid flows, the internal flow path including a folded portion, an inflow-side connection portion which communicates with the internal flow path and into which the second fluid flows, an outflow-side connection portion which communicates with the internal flow path and from which the second fluid flows out, a plurality of slits provided in a portion of the heat exchange tube between two flow path portions in the internal flow paths, the two flow path portions each extending from the folded portion and facing each other at an interval, and a plurality of protruding support portions in contact with another adjacent heat exchange tube to form the gap. As viewed in a stacking direction of the plurality of heat exchange tubes, at least one of the plurality of slits extends in a state where a center in an extending direction of the plurality of slits deviates from a straight line connecting the two adjacent protruding support portions.

According to this aspect, in the heat exchanger configured by stacking the plurality of heat exchange tubes, the gap between the heat exchange tubes can be accurately formed.

For example, as viewed in the stacking direction, at least one of the plurality of slits may extend without intersecting a straight line connecting the two adjacent protruding support portions.

For example, as viewed in the stacking direction, the plurality of slits may extend avoiding the center line of the heat exchange tube which passes between the inflow-side connection portion and the outflow-side connection portion.

For example, as viewed in the stacking direction, the plurality of slits may be provided in the heat exchange tube symmetrically with respect to a center line.

For example, the heat exchange tube may include a cut-and-raised portion, and the slit may be a through hole in the cut-and-raised portion.

For example, the cut-and-raised piece in the cut-and-raised portion may have a wall shape rising on the downstream side in the flow direction of the first fluid with respect to the through hole and inclined toward the upstream side in the flow direction.

For example, the cut-and-raised piece in the cut-and-raised portion may have a bridge shape extending in a direction orthogonal to the flow direction of the first fluid.

For example, the inflow-side connection portion and the outflow-side connection portion may be adjacent to each other, and as viewed in the stacking direction, a through hole may be provided in a portion of the heat exchange tube between the inflow-side connection portion and the outflow-side connection portion.

For example, the inflow-side connection portion and the outflow-side connection portion may be side by side in the flow direction of the first fluid.

For example, the inflow-side connection portion may be positioned on the downstream side in the flow direction of the first fluid, and the outflow-side connection portion may be positioned on the upstream side.

Hereinafter, preferred embodiments of the present disclosure will be described with reference to the drawings.

First Preferred Embodiment

FIG. 1 is a front view of a heat exchanger according to the present first preferred embodiment. In addition, FIG. 2 is a partial cross-sectional view of the heat exchanger taken along line A-A in FIG. 1. It should be noted that the X-Y-Z orthogonal coordinate system shown in the drawings is for facilitating understanding of the present disclosure, and does not limit the preferred embodiments of the present disclosure. The X-axis direction indicates a lateral direction of the heat exchange tube, the Y-axis direction indicates a longitudinal direction of the heat exchange tube, and the Z-axis direction indicates a stacking direction of the plurality of heat exchange tubes.

The heat exchanger 10 shown in FIG. 1 is used for a cooling apparatus or the like of an apparatus that operates accompanied by refrigeration cycle and heat generation, such as an air conditioning apparatus or a refrigeration apparatus. Specifically, in the present first preferred embodiment, the heat exchanger 10 is an apparatus for heating or cooling fluid (second fluid) F2 such as water or hydrofluorocarbon by fluid (first fluid) F1 such as air.

As shown in FIGS. 1 and 2, the heat exchanger 10 includes a plurality of heat exchange tubes 20 stacked with gaps through which the first fluid F1 can pass, and a casing 22 that supports the heat exchange tubes 20. FIG. 3 is a perspective view of the heat exchange tube of the heat exchanger according to the first preferred embodiment. In addition, FIG. 4 is a top view of the heat exchange tube of the heat exchanger according to the first preferred embodiment. Then, FIG. 5 is a cross-sectional view of the heat exchange tube taken along line B-B in FIG. 4. It should be noted that FIG. 5 shows a state in which two heat exchange tubes are stacked.

As shown in FIGS. 3 to 4, the heat exchange tube 20 is a member having a substantially thin plate shape, what is called a fin shape, and is a member that performs heat exchange with the first fluid F1.

As shown in FIG. 5, the heat exchange tube 20 is formed, for example, by joining two press-molded metal thin plates 20A and 20B to each other. In the case of the present first preferred embodiment, the metal thin plates 20A and 20B used for the heat exchange tube 20 are aluminum substrates having a brazing material layer such as an aluminum silicon alloy formed on both surfaces and a thickness of 0.2 mm, what is called clad plates. Embossed portions 20 a and 20 b are formed on the two metal thin plates 20A and 20B, respectively, by press molding. Joining the two metal thin plates 20A and 20B in a state where the embossed portions 20 a and 20 b face each other forms the internal flow path 26 of the heat exchange tube 20. It should be noted that the heat exchange tube 20 may be made of a clad material having a brazing material layer of copper, nickel, or the like formed on both surfaces of a stainless substrate, or may be made of a copper substrate having a brazing material joined or plated on both surfaces.

As shown in FIGS. 3 to 5, the heat exchange tube 20 includes a tubular inflow-side connection portion 28 that communicates with the internal flow path 26 and into which the second fluid F2 flows, and a tubular outflow-side connection portion 30 that communicates with the internal flow path 26 and from which the second fluid F2 flows out. In the case of the present Embodiment 1, the inflow-side connection portion 28 and the outflow-side connection portion 30 are arranged side by side in the lateral direction (X-axis direction) at the center in the longitudinal direction (Y-axis direction) of the heat exchange tube 20. When the plurality of heat exchange tubes 20 are stacked, the inflow-side connection portions 28 of the plurality of heat exchange tubes 20 are coupled in the stacking direction (Z-axis direction), and the outflow-side connection portions 30 are coupled in the stacking direction. The inflow-side connection portions 28 are heating-joined to each other, for example, brazed, and the outflow-side connection portions 30 are heating-joined to each other, for example, brazed. As shown in FIG. 2, coupling the plurality of inflow-side connection portions 28 forms an inflow-side manifold flow path 32 for distributing the second fluid F2 to the internal flow path 26 of each of the heat exchange tubes 20. In addition, coupling the plurality of outflow-side connection portions 30 forms an outflow-side manifold flow path 34 for merging the second fluid F2 from the internal flow path 26 of each of the heat exchange tubes 20.

It should be noted that as in the present first preferred embodiment, it is preferable that the inflow-side connection portion 28 and the outflow-side connection portion 30 are side by side in the flow direction of the first fluid F1 (X-axis direction), that is, overlap each other in the flow direction. Thus, it is possible to reduce the flow path resistance with respect to the first fluid F1 flowing through the gap S between the heat exchange tubes 20 as compared with a case where the inflow-side connection portion 28 and the outflow-side connection portion 30 are not side by side in the flow direction.

In addition, in consideration of the heat exchange rate between the first fluid F1 and the second fluid F2, it is preferable that the inflow-side connection portion 28 is positioned on the downstream side in the flow direction of the first fluid F1 (X-axis direction) and the outflow-side connection portion 30 is positioned on the upstream side in the flow direction of the first fluid F1. As shown in FIG. 3, the second fluid F2 flowing from the inflow-side connection portion 28 to the outflow-side connection portion 30 through the internal flow path 26 flows in a direction opposite to the flow direction of the first fluid F1 as viewed in the stacking direction (Z-axis direction) of the heat exchange tubes 20. As a result, the flow of the second fluid F2 can be regarded as a counter flow to the flow of the first fluid F1. As a result, the heat exchange rate between the first and second fluids F1 and F2 is improved as compared with the case where the first and second fluids F1 and F2 flow in the same direction as viewed in the stacking direction, that is, as compared with the case where the inflow-side connection portion 28 is positioned on the upstream side in the flow direction of the first fluid F1 and the outflow-side connection portion 30 is positioned on the downstream side.

As shown in FIGS. 1 and 2, the plurality of heat exchange tubes in the stacked state are accommodated in the casing 22. The casing 22 has a tubular shape opened in the lateral direction (X-axis direction) of the heat exchange tube 20, so that the flow direction of the first fluid F1 is regulated in the lateral direction of the heat exchange tube 20.

In addition, in the case of the present first preferred embodiment, the casing 22 includes a top plate portion 22 a, a bottom plate portion 22 b, and a side wall portion 22 c connecting the top plate portion 22 a and the bottom plate portion 22 b. Heating and joining to each other the top plate portion 22 a, the plurality of heat exchange tubes 20, and the bottom plate portion 22 b in a stacked state manufactures a stacked body thereof. Thereafter, fixing the side wall portion 22 c to the top plate portion 22 a and the bottom plate portion 22 b of the stacked body with screws or the like manufactures the heat exchanger 10.

In addition, the casing 22 includes an inflow port 36 communicating with the inflow-side manifold flow path 32 and an outflow port 38 communicating with the outflow-side manifold flow path 34. The second fluid F2 enters the inflow-side manifold flow path 32 through the inflow port 36, and enters the internal flow path 26 of each of the heat exchange tubes 20 from the inflow-side manifold flow path 32. The second fluid F2 in the internal flow path 26 of each of the heat exchange tubes 20 merges in the outflow-side manifold flow path 34 and flows out to the outside of the heat exchanger 10 through the outflow port 38.

As shown in FIG. 5, the plurality of heat exchange tubes 20 are stacked with a gap S through which the first fluid F1 can pass. In order to form and maintain the gap S, each of the heat exchange tubes 20 includes a plurality of protruding support portions 40 and 42 on both surfaces in the stacking direction (Z-axis direction). The plurality of protruding support portions 40 are provided on one surface (metal thin plate 20A) of the heat exchange tube 20, and the plurality of protruding support portions 42 are provided on the other surface (metal thin plate 20B). In addition, the positions of the plurality of protruding support portions 40 and the positions of the plurality of protruding support portions 42 coincide with each other as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20.

The plurality of protruding support portions 42 of the heat exchange tube 20 and the plurality of protruding support portions 44 of the adjacent heat exchange tube 20 are in contact with each other and support each other, whereby the gap S through which the first fluid F1 can pass is formed between the two heat exchange tubes 20. The protruding support portion 42 and the protruding support portion 44 are heating-joined, for example, brazed.

As shown in FIG. 4, in the case of the present first preferred embodiment, the internal flow path 26 of the heat exchange tube 20 has a shape symmetrical about a center line C1 extending in the lateral direction (X-axis direction) of the heat exchange tube 20 and symmetrical about a center line C2 extending in the longitudinal direction (Y-axis direction) as viewed in the stacking direction (Z-axis direction). Specifically, the internal flow path 26 includes a substantially “M”-shaped flow path 26L extending from the inflow-side connection portion 28 toward the outflow-side connection portion 30 and arranged on one side in the longitudinal direction of the heat exchange tube 20, and a substantially “M”-shaped flow path 26R extending from the inflow-side connection portion 28 toward the outflow-side connection portion 30 and arranged on the other side in the longitudinal direction. As a result, the internal flow path 26 includes a plurality of folded portions 26 a in which the flow direction of the second fluid F2 changes by 180 degrees. Since the internal flow path 26 includes the plurality of folded portions 26 a, a heat exchange rate between the second fluid F2 flowing in the internal flow path 26 and the first fluid F1 flowing on the heat exchange tube 20 is improved.

As shown in FIG. 4, the heat exchange tube 20 is provided with a plurality of slits 46. Specifically, a plurality of slits 46 are formed in a portion, between the two flow path portions 26 b in the internal flow path 26 which extend from the folded portion 26 a and face each other at an interval, of the heat exchange tube 20. In the case of the present first preferred embodiment, the slit 46 is an elongated hole that extends in the extending direction (Y-axis direction) of the linear flow path portion 26 b and penetrates the heat exchange tube 20. The slit 46 is formed in the heat exchange tube 20 by punching, for example.

The slit 46 is provided to suppress heat exchange between the second fluids F2 flowing through the respective two flow path portions 26 b extending from the folded portion 26 a. That is, the slit 46 suppresses heat transfer through the heat exchange tube 20 from the second fluid F2 in one flow path portion 26 b to the second fluid F2 in the other flow path portion 26 b. In other words, the slit 46 suppresses a heat shortcut. Since occurrence of such a heat shortcut decreases the heat exchange rate between the first and second fluids F1 and F2, the slit 46 is provided as a countermeasure.

A heat shortcut can be suppressed with this slit 46, but the heat exchange tube 20 is likely to be deformed as compared with a case where there is no slit. Thus, the plurality of slits 46 are provided at appropriate positions so that deformation of the heat exchange tube 20 can be suppressed.

Specifically, as shown in FIG. 4, as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20, at least one slit 46 is provided in the heat exchange tube 20 in a state where the center in the extending direction (Y-axis direction) of the slit 46 deviates from the straight line connecting the two adjacent protruding support portions 40. Its reason will be described.

FIG. 6A shows a simplified model of a heat exchange tube of a comparative example provided with a slit and two protruding support portions. FIG. 6B shows a simplified model of a heat exchange tube of a comparative example torsionally deformed by stacking.

As shown in FIG. 6A, when the center CS in the extending direction (Y-axis direction) of the slit 146 is positioned on the straight line VL connecting the two adjacent protruding support portions 140, for example, adjacent at the shortest distance, the heat exchange tube 120 of the comparative example is easily deformed.

As described above, the plurality of heat exchange tubes 120 of the comparative example are stacked in a state where each of them is supported by each other via the protruding support portions 140 and 142. However, when an allowable manufacturing error (for example, height errors of the protruding support portions 140 and 142, and the like.) of each of the heat exchange tubes 120 and an allowable assembly error of the plurality of heat exchange tubes 120 accumulate, deformation may occur in a certain heat exchange tube 120.

For example, as shown in FIG. 6B, due to accumulation of errors, torsional deformation may occur such that the positions (height positions) in the stacking direction (Z-axis direction) of the two adjacent protruding support portions 140 are different in the heat exchange tube 120. This occurs because the two protruding support portions 140 are not constrained to each other by the slit 146 and are likely to shift in the stacking direction with respect to each other. When such torsional deformation occurs, the size of the gap between the heat exchange tubes 120 may cause variation, so that the flow path resistance to the first fluid passing through the gap may cause variation. As a result, the heat exchange rate of the heat exchanger may cause variation.

Such torsional deformation is likely to occur when the center CS in the extending direction (Y-axis direction) of the slit 146 is positioned on the straight line VL connecting the two adjacent protruding support portions 140 as shown in FIG. 6A. In addition, the larger the length of the slit 146, the larger the deformation amount of the heat exchange tube 120.

Thus, in the case of the present first preferred embodiment, as shown in FIG. 4, as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20, at least one slit 46 is provided in the heat exchange tube 20 in a state where the center in the extending direction (Y-axis direction) of the slit 46 deviates from the straight line connecting the two adjacent protruding support portions 40.

FIG. 7A is a diagram showing a simplified model of the heat exchange tube of the example. In addition, FIG. 7B is a diagram showing a simplified model of the heat exchange tube of the preferred example.

In the heat exchange tube 20 of the example shown in FIG. 7A, as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20, the center CS in the extending direction (Y-axis direction) of the slit 46 is deviated from the straight line VL connecting the two adjacent protruding support portions 40. As a result, as compared with the heat exchange tube 120 of the comparative example shown in FIG. 6A in which the center CL is positioned on the straight line VL, the heat exchange tube 20 is prevented from deformation caused by stacking.

It should be noted that the deformation of the heat exchange tube 20 is further suppressed as the straight line VL connecting the two adjacent protruding support portions 40 is farther from the center CS of the slit 46 and closer to both ends of the slit 46.

In the heat exchange tube 20 of the preferred embodiment shown in FIG. 7B, as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20, the slit 46 extends without intersecting the straight line VL connecting the two adjacent protruding support portions 40. Accordingly, since the slit 46 does not exist between the two protruding support portions 40, the two protruding support portions are made difficult to shift in the stacking direction with respect to each other. As a result, the heat exchange tube 20 shown in FIG. 7B is further less likely to be deformed than the heat exchange tube 20 of the example shown in FIG. 7A.

In addition to being positioned with respect to the plurality of protruding support portions 40 (42) in order to suppress deformation of the heat exchange tube 20, the slit 46 is provided in the heat exchange tube 20 in consideration of the following in the case of the present first preferred embodiment.

First, in the case of the present first preferred embodiment, as shown in FIG. 4, the plurality of slits 46 are provided in the heat exchange tube 20 so as to extend avoiding the center line C2 that extends in the longitudinal direction (Y-axis direction) of the heat exchange tube 20. That is, the plurality of slits 46 are provided in the heat exchange tube 20 so as to extend avoiding the center line C2 that passes between the inflow-side connection portion 28 and the outflow-side connection portion 30. Thus, when the plurality of heat exchange tubes 20 are stacked, bending of a certain heat exchange tube 20 along the center line C2 is suppressed.

Specifically, there is an allowable error in the size in the stacking direction (Z-axis direction) in the inflow-side connection portion 28 and the outflow-side connection portion 30 of each of the heat exchange tubes 20. When the plurality of heat exchange tubes 20 are stacked and errors thereof are accumulated, bending stress occurs between the inflow-side connection portion 28 and the outflow-side connection portion 30 in a certain heat exchange tube 20. At this time, when the plurality of slits 46 extend on the center line C2 of the heat exchange tube 20 passing between the inflow-side connection portion 28 and the outflow-side connection portion 30, the heat exchange tube 20 may be bent along the center line C2.

Therefore, as shown in FIG. 4, the plurality of slits 46 are provided in the heat exchange tube 20 avoiding the center line C2 that passes between the inflow-side connection portion 28 and the outflow-side connection portion 30.

In addition, in the case of the present first preferred embodiment, as shown in FIG. 4, the plurality of slits 46 are arranged symmetrically with respect to two center lines C1 and C2 of the heat exchange tube 20 as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20. Accordingly, rigidity of the heat exchange tube 20 becomes uniform, and deformation of the heat exchange tube 20 is suppressed.

In the case of the present first preferred embodiment, the heat exchange tube 20 also includes a component other than the slit 46 as a component that suppresses a heat shortcut.

As shown in FIG. 4, as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20, the inflow-side connection portion 28 and the outflow-side connection portion 30 are adjacent to each other at a close distance in a state where there is no internal flow path 26 therebetween. A through hole 48 for suppressing heat transfer between the second fluid F2 flowing through the inflow-side connection portion 28 and the second fluid F2 flowing through the outflow-side connection portion 30 is provided in a portion of the heat exchange tube 20 therebetween.

Specifically, in the heat exchange tube 20, the temperature difference between the second fluid F2 flowing through the inflow-side connection portion 28 and the second fluid F2 flowing through the outflow-side connection portion 30 is the largest. Therefore, when the inflow-side connection portion 28 and the outflow-side connection portion 30 are adjacent to each other, a large amount of heat shortcut may occur therebetween. In order to suppress the heat shortcut, a through hole 48 is provided.

Furthermore, in the case of the present first preferred embodiment, as shown in FIG. 4, as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20, also in a portion of the heat exchange tube 20 between the inflow-side connection portion 28 and the internal flow path 26, and a portion of the heat exchange tube 20 between the outflow-side connection portion 30 and the internal flow path 26, through holes 50 for suppressing a heat shortcut therebetween are provided.

According to the present first preferred embodiment as described above, in the heat exchanger configured by stacking the plurality of heat exchange tubes, the gap between the heat exchange tubes can be accurately formed.

Second Preferred Embodiment

In the case of the first preferred embodiment described above, as shown in FIG. 5, the slit 46 has a through-hole shape formed by removing a part of the heat exchange tube 20 by, for example, punching. The present second preferred embodiment is different from the first preferred embodiment in the method for forming the slit. The present second preferred embodiment will be described focusing on this different point.

FIG. 8 is a cross-sectional view of the heat exchange tube of the heat exchanger according to the present second preferred embodiment. It should be noted that FIG. 8 shows a state in which two heat exchange tubes are stacked.

As shown in FIG. 8, the slit 252 b is also provided in the heat exchange tube 220 for the same reason as the slit 46 of the heat exchange tube 20 of the first preferred embodiment described above. However, the slit 252 b of the present second preferred embodiment includes part of the cut-and-raised portion 252.

The cut-and-raised portion 252 includes, for example, a cut-and-raised piece 252 a formed by forming a square bracket-shaped cut in the heat exchange tube 220 and raising a portion surrounded by the cut, and a through hole caused by the cut-and-raised piece 252 a rising. The through hole in the cut-and-raised portion 252 functions as, a slit 252 b that suppresses a heat shortcut between the second fluids F2 flowing through different portions (portions extending from the folded portion and facing each other) of the internal flow path 226.

In addition, in the case of the present second preferred embodiment, the cut-and-raised piece 252 a in the cut-and-raised portion 252 has a wall shape that is raised on the downstream side in the flow direction of the first fluid F1 with respect to the slit 252 b (through hole) and is inclined toward the upstream side in the flow direction. Therefore, the cut-and-raised piece 252 a functions as a wind direction plate for the first fluid F1. Specifically, the cut-and-raised piece 252 a guides the first fluid F1 into the slit 252 b. Thus, the first fluid F1 flows into a different gap S of the heat exchange tubes 20. As a result, the first fluid F1 flows in the heat exchanger in a complicated manner, so that the heat exchange rate between the first fluid F1 and the second fluid F2 is improved as compared with the first preferred embodiment described above.

Also in the present second preferred embodiment, as in the first preferred embodiment described above, a gap between heat exchange tubes can be accurately formed in a heat exchanger configured by stacking a plurality of heat exchange tubes.

Third Preferred Embodiment

The present third preferred embodiment is an improved form of the second preferred embodiment described above. Specifically, the shape of the cut-and-raised piece in the cut-and-raised portion is different.

FIG. 9 is a perspective view of a heat exchange tube according to the present third preferred embodiment. In addition, FIG. 10 is a cross-sectional view of the heat exchange tube of the heat exchanger according to the present third preferred embodiment. It should be noted that. FIG. 10 shows a state in which two heat exchange tubes are stacked.

As shown in FIGS. 9 and 10, the heat exchange tube 320 of the heat exchanger according to the present third preferred embodiment also includes a cut-and-raised portion 352 as with the heat exchange tube 220 of the second preferred embodiment described above. In the case of the present third preferred embodiment, the cut-and-raised piece 352 a in the cut-and-raised portion 352 has a bridge shape extending in a direction orthogonal to the flow direction of the first fluid F1. The through hole 352 b in the cut-and-raised portion 352 functions as a slit that suppresses a heat shortcut between the second fluids F2 flowing through different portions (portions extending from the folded portion and facing each other) of the internal flow path 326.

As shown in FIG. 10, the first fluid F1 is divided into upper and lower flows by the bridge-shaped cut-and-raised piece 352 a. Thus, the first fluid F1 flows more complicatedly in the heat exchanger than in the second preferred embodiment described above, thereby further improving the heat exchange rate between the first fluid F1 and the second fluid F2.

Also in the present third preferred embodiment, as in the first preferred embodiment described above, a gap between heat exchange tubes can be accurately formed in a heat exchanger configured by stacking a plurality of heat exchange tubes.

Although the present disclosure has been described above with reference to the above-described first to third preferred embodiments, the preferred embodiment of the present disclosure is not limited to the above-described preferred embodiments.

For example, in the case of the above-described first preferred embodiment, as shown in FIG. 4, the internal flow path 26 of the heat exchange tube 20 has a symmetrical shape with respect to the center line C1 extending in the lateral direction (X-axis direction) and the center line C2 extending in the longitudinal direction (Y-axis direction) as viewed in the stacking direction (Z-axis direction) of the plurality of heat exchange tubes 20. Specifically, the internal flow path 26 includes a substantially “M”-shaped flow path 26L arranged on one side in the longitudinal direction of the heat exchange tube 20 and a substantially “M”-shaped flow path 26R arranged on the other side in the longitudinal direction.

However, the shape of the internal flow path of the heat exchange tube in the heat exchanger according to the preferred embodiment of the present disclosure is not limited to this.

FIGS. 11, 12, and 13 are diagrams showing various examples of an internal flow path of a heat exchange tube.

In the case of the heat exchange tube 420 shown in FIG. 11, the internal flow path 426 has a symmetrical shape with respect to a center line C1 extending in the lateral direction (X-axis direction) and a center line C2 extending in the longitudinal direction (Y-axis direction) as viewed in the stacking direction (Z-axis direction) of the heat exchange tubes 420. Specifically, the internal flow path 426 includes a substantially “U”-shaped flow path 426L extending from the inflow-side connection portion 428 toward the outflow-side connection portion 430 and arranged on one side in the longitudinal direction of the heat exchange tube 20, and a substantially “U”-shaped flow path 426R extending from the inflow-side connection portion 428 toward the outflow-side connection portion 430 and arranged on the other side in the longitudinal direction. Thus, the internal flow path 426 includes two folded portions 426 a and flow path portions 426 b extending from the folded portions 426 a and facing each other at an interval. A plurality of slits 446 are provided in a portion of the heat exchange tube 420 between the flow path portions 426 b.

In the case of the heat exchange tube 520 shown in FIG. 12, the internal flow path 526 has a symmetrical shape with respect to the center line C2 extending in the longitudinal direction (Y-axis direction) as viewed in the stacking direction (Z-axis direction) of the heat exchange tubes 520. However, the shape of the internal flow path 526 is not symmetrical with respect to the center line C1 extending in the lateral direction (X-axis direction). This is because the inflow-side connection portion 528 and the outflow-side connection portion 530 are provided side by side in the lateral direction at one end portion in the longitudinal direction rather than at the center in the longitudinal direction in the heat exchange tube 520. The internal flow path 526 extends from the inflow-side connection portion 528 toward the outflow-side connection portion 530 and has a substantially “M” shape. Thus, the internal flow path 526 includes three folded portions 526 a and flow path portions 526 b extending from the folded portions 526 a and facing each other at an interval. A plurality of slits 546 are provided in a portion of the heat exchange tube 520 between the flow path portions 526 b. It should be noted that the plurality of slits 546 are provided avoiding the center line C2.

In the case of the heat exchange tube 620 shown in FIG. 13, the shape of the internal flow path 626 is not symmetrical with respect to the center line C1 extending in the lateral direction (X-axis direction) and the center line C2 extending in the longitudinal direction (Y-axis direction) as viewed in the stacking direction (Z-axis direction) of the heat exchange tubes 620. This is because the inflow-side connection portion 628 and the outflow-side connection portion 630 are disposed on a diagonal line of the heat exchange tube 620. Therefore, the internal flow path 626 extends from the inflow-side connection portion 628 toward the outflow-side connection portion 630 and has an “inverted S” shape. Thus, the internal flow path 626 includes two folded portions 626 a and flow path portions 626 b extending from the folded portions 626 a and facing each other at an interval. A plurality of slits 646 are provided in a portion of the heat exchange tube 620 between the flow path portions 626 b.

As described above, the shape of the internal flow path and the positions of the inflow-side connection portion and the outflow-side connection portion of the heat exchanger can be variously changed according to the application. The internal flow path of the heat exchange tube in the heat exchanger according, to the preferred embodiments of the present disclosure has only to be a flow path including at least one folded portion. That is, the heat exchange tube in the heat exchanger according to the preferred embodiment of the present disclosure is a heat exchange tube in which two flow path portions facing each other at an interval are generated by one folded portion, and a slit is provided in a portion of the heat exchange tube between the two flow path portions.

In addition, in the case of the above-described first preferred embodiment, as shown in FIG. 3, the first fluid F1 to be heat-exchanged by the heat exchanger 10 flows in the lateral direction (X-axis direction) of the heat exchange tube 20. However, the preferred embodiment of the present disclosure is not limited thereto. The heat exchanger may be configured such that the first fluid flows in a longitudinal direction of the heat exchange tube.

That is, in a broad sense, a heat exchanger according to a preferred embodiment of the present disclosure includes a plurality of heat exchange tubes stacked with a gap through which a first fluid is configured to pass. Each of the heat exchange tubes includes: an internal flow path through which a second fluid for exchanging heat with the first fluid flows, the internal flow path including a folded portion, an inflow-side connection portion which communicates with the internal flow path and into which the second fluid flows, an outflow-side connection portion which communicates with the internal flow path and from which the second fluid flows out, a plurality of slits provided in a portion of the heat exchange tube between two flow path portions in the internal flow paths, the two flow path portions each extending from the folded portion and facing each other at an interval, and a plurality of protruding support portions in contact with another adjacent heat exchange tube to form the gap. As viewed in a stacking direction of the plurality of heat exchange tubes, at least one of the plurality of slits extends in a state where a center in an extending direction of the plurality of slits deviates from a straight line connecting the two adjacent protruding support portions.

As described above, the above-described preferred embodiments have been described as the exemplification of the technique in the present disclosure. To that end, drawings and a detailed description are provided. Therefore, among the components described in the drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem may be included in order to exemplify the above technique. Therefore, it should not be recognized that these non-essential components are essential immediately because these non-essential components are described in the drawings and the detailed description.

In addition, since the above preferred embodiments are for exemplifying the technique in the present disclosure, various changes, substitutions, additions, omissions, and the like can be made within the scope of the claims or the equivalent thereof.

The present disclosure is applicable to a heat exchanger configured by stacking a plurality of fin-shaped heat exchange tubes. 

What is claimed is:
 1. A heat exchanger comprising a plurality of heat exchange tubes stacked with a gap through which a first fluid is passable, each of the heat exchange tubes including: an internal flow path through which a second fluid for exchanging heat with the first fluid flows, the internal flow path including a folded portion; an inflow-side connection portion which communicates with the internal flow path and into which the second fluid flows; an outflow-side connection portion which communicates with the internal flow path and from which the second fluid flows out; a plurality of slits provided in a portion of the heat exchange tube between two flow path portions in the internal flow paths, the two flow path portions respectively extending from the folded portions and facing each other at an interval; and a plurality of protruding support portions in contact with another adjacent heat exchange tube to form the gap, wherein as viewed in a stacking direction of the plurality of heat exchange tubes, at least one of the plurality of slits extends in a state where a center in an extending direction of the plurality of slits deviates from a straight line connecting the two adjacent protruding support portions.
 2. The heat exchanger according to claim 1, wherein as viewed in the stacking direction, at least one of the plurality of slits extends without intersecting a straight line connecting the two adjacent protruding support portions.
 3. The heat exchanger according to claim 1, wherein as viewed in the stacking direction, the plurality of slits extends avoiding a centerline of the heat exchange tube which passes between the inflow-side connection portion and the outflow-side connection portion.
 4. The heat exchanger according to claim 1, wherein as viewed in the stacking direction, the plurality of slits are provided in the heat exchange tube symmetrically with respect to a center line.
 5. The heat exchanger according to claim 1, wherein the heat exchange tube includes a cut-and-raised portion, and wherein each of the slits is a through hole in the cut-and-raised portion.
 6. The heat exchanger according to claim 5, wherein a cut-and-raised piece in the cut-and-raised portion has a wall shape rising on a downstream side in a flow direction of the first fluid with respect to the through hole and inclined toward an upstream side in the flow direction.
 7. The heat exchanger according to claim 5, wherein a cut-and-raised piece in the cut-and-raised portion has a bridge shape extending in a direction orthogonal to a flow direction of the first fluid.
 8. The heat exchanger according to claim 1, wherein the inflow-side connection portion and the outflow-side connection portion are adjacent to each other, and wherein as viewed in the stacking direction, a through hole is provided in a portion of the heat exchange tube between the inflow-side connection portion and the outflow-side connection portion.
 9. The heat exchanger according to claim 1, wherein the inflow-side connection portion and the outflow-side connection portion are side by side in a flow direction of the first fluid.
 10. The heat exchanger according to claim 9, wherein the inflow-side connection portion is positioned on a downstream side in a flow direction of the first fluid, and the outflow-side connection portion is positioned on an upstream side. 